/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @author       Felipe Alfonso <@bitnenfer>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Class = require('../../utils/Class');
var DeepCopy = require('../../utils/object/DeepCopy');
var GetFastValue = require('../../utils/object/GetFastValue');
var Matrix4 = require('../../math/Matrix4');
var Utils = require('./Utils');
var WebGLShader = require('./WebGLShader');

/**
 * @classdesc
 * The `WebGLPipeline` is a base class used by all of the core Phaser pipelines.
 *
 * It describes the way elements will be rendered in WebGL. Internally, it handles
 * compiling the shaders, creating vertex buffers, assigning primitive topology and
 * binding vertex attributes, all based on the given configuration data.
 *
 * The pipeline is configured by passing in a `WebGLPipelineConfig` object. Please
 * see the documentation for this type to fully understand the configuration options
 * available to you.
 *
 * Usually, you would not extend from this class directly, but would instead extend
 * from one of the core pipelines, such as the Multi Pipeline.
 *
 * The pipeline flow per render-step is as follows:
 *
 * 1) onPreRender - called once at the start of the render step
 * 2) onRender - call for each Scene Camera that needs to render (so can be multiple times per render step)
 * 3) Internal flow:
 * 3a)   bind (only called if a Game Object is using this pipeline and it's not currently active)
 * 3b)   onBind (called for every Game Object that uses this pipeline)
 * 3c)   flush (can be called by a Game Object, internal method or from outside by changing pipeline)
 * 4) onPostRender - called once at the end of the render step
 *
 * @class WebGLPipeline
 * @memberof Phaser.Renderer.WebGL
 * @constructor
 * @since 3.0.0
 *
 * @param {Phaser.Types.Renderer.WebGL.WebGLPipelineConfig} config - The configuration object for this WebGL Pipeline.
 */
var WebGLPipeline = new Class({

    initialize:

    function WebGLPipeline (config)
    {
        var game = config.game;
        var renderer = game.renderer;
        var gl = renderer.gl;

        /**
         * Name of the pipeline. Used for identification and setting from Game Objects.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#name
         * @type {string}
         * @since 3.0.0
         */
        this.name = GetFastValue(config, 'name', 'WebGLPipeline');

        /**
         * The Phaser Game instance to which this pipeline is bound.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#game
         * @type {Phaser.Game}
         * @since 3.0.0
         */
        this.game = game;

        /**
         * The WebGL Renderer instance to which this pipeline is bound.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#renderer
         * @type {Phaser.Renderer.WebGL.WebGLRenderer}
         * @since 3.0.0
         */
        this.renderer = renderer;

        /**
         * The WebGL context this WebGL Pipeline uses.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#gl
         * @type {WebGLRenderingContext}
         * @since 3.0.0
         */
        this.gl = gl;

        /**
         * The canvas which this WebGL Pipeline renders to.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#view
         * @type {HTMLCanvasElement}
         * @since 3.0.0
         */
        this.view = game.canvas;

        /**
         * Width of the current viewport.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#width
         * @type {number}
         * @since 3.0.0
         */
        this.width = 0;

        /**
         * Height of the current viewport.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#height
         * @type {number}
         * @since 3.0.0
         */
        this.height = 0;

        /**
         * The current number of vertices that have been added to the pipeline batch.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#vertexCount
         * @type {number}
         * @default 0
         * @since 3.0.0
         */
        this.vertexCount = 0;

        /**
         * The total number of vertices that this pipeline batch can hold before it will flush.
         *
         * This defaults to `renderer batchSize * 7`, where `batchSize` is defined in the Renderer Config.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#vertexCapacity
         * @type {number}
         * @since 3.0.0
         */
        this.vertexCapacity = 0;

        /**
         * Raw byte buffer of vertices.
         *
         * Either set via the config object, or generates a new Array Buffer of size `vertexCapacity * vertexSize`.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#vertexData
         * @type {ArrayBuffer}
         * @readonly
         * @since 3.0.0
         */
        this.vertexData;

        /**
         * The WebGLBuffer that holds the vertex data.
         *
         * Created from the `vertices` config ArrayBuffer that was passed in, or set by default, by the pipeline.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#vertexBuffer
         * @type {WebGLBuffer}
         * @readonly
         * @since 3.0.0
         */
        this.vertexBuffer;

        /**
         * The primitive topology which the pipeline will use to submit draw calls.
         *
         * Defaults to GL_TRIANGLES if not otherwise set in the config.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#topology
         * @type {GLenum}
         * @since 3.0.0
         */
        this.topology = GetFastValue(config, 'topology', gl.TRIANGLES);

        /**
         * Uint8 view to the `vertexData` ArrayBuffer. Used for uploading vertex buffer resources to the GPU.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#bytes
         * @type {Uint8Array}
         * @since 3.0.0
         */
        this.bytes;

        /**
         * Float32 view of the array buffer containing the pipeline's vertices.
         *
         * @name Phaser.Renderer.WebGL.Pipelines.MultiPipeline#vertexViewF32
         * @type {Float32Array}
         * @since 3.0.0
         */
        this.vertexViewF32;

        /**
         * Uint32 view of the array buffer containing the pipeline's vertices.
         *
         * @name Phaser.Renderer.WebGL.Pipelines.MultiPipeline#vertexViewU32
         * @type {Uint32Array}
         * @since 3.0.0
         */
        this.vertexViewU32;

        /**
         * Indicates if the current pipeline is active, or not, for this frame only.
         *
         * Reset to `true` in the `onRender` method.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#active
         * @type {boolean}
         * @since 3.10.0
         */
        this.active = false;

        /**
         * Holds the most recently assigned texture unit.

         * Treat this value as read-only.
         *
         * @name Phaser.Renderer.WebGL.Pipelines.WebGLPipeline#currentUnit
         * @type {number}
         * @since 3.50.0
         */
        this.currentUnit = 0;

        /**
         * Some pipelines require the forced use of texture zero (like the light pipeline).
         *
         * This property should be set when that is the case.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#forceZero
         * @type {boolean}
         * @since 3.50.0
         */
        this.forceZero = false;

        /**
         * Indicates if this pipeline has booted or not.
         *
         * A pipeline boots only when the Game instance itself, and all associated systems, is
         * fully ready.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#hasBooted
         * @type {boolean}
         * @readonly
         * @since 3.50.0
         */
        this.hasBooted = false;

        /**
         * The WebGLFramebuffer this pipeline is targeting, if any.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#targetFramebuffer
         * @type {?WebGLFramebuffer}
         * @since 3.50.0
         */
        this.targetFramebuffer = null;

        /**
         * The WebGLTexture this pipeline is targeting, if any.
         *
         * @name Phaser.GameObjects.Shader#targetTexture
         * @type {?WebGLTexture}
         * @since 3.50.0
         */
        this.targetTexture = null;

        /**
         * When using a targetTexture its dimensions are based on the scale of the WebGLRenderer.
         *
         * This value controls how much those dimensions are scaled.
         *
         * @name Phaser.GameObjects.Shader#targetScale
         * @type {number}
         * @since 3.50.0
         */
        this.targetScale = GetFastValue(config, 'targetScale', 1);

        /**
         * An array of all the WebGLShader instances that belong to this pipeline.
         *
         * All shaders must use the same attributes, as set by this pipeline, but can manage their own
         * uniforms.
         *
         * These are set in a call to the `setShadersFromConfig` method, which happens automatically,
         * but can also be called at any point in your game. See the method documentation for details.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#shaders
         * @type {Phaser.Renderer.WebGL.WebGLShader[]}
         * @since 3.50.0
         */
        this.shaders = [];

        /**
         * A reference to the currently bound WebGLShader instance from the `WebGLPipeline.shaders` array.
         *
         * For lots of pipelines, this is the only shader, so it is a quick way to reference it without
         * an array look-up.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#currentShader
         * @type {Phaser.Renderer.WebGL.WebGLShader}
         * @since 3.50.0
         */
        this.currentShader;

        /**
         * The Model matrix, used by shaders as 'uModelMatrix' uniform.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#modelMatrix
         * @type {Phaser.Math.Matrix4}
         * @since 3.50.0
         */
        this.modelMatrix = new Matrix4().identity();

        /**
         * The View matrix, used by shaders as 'uViewMatrix' uniform.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#viewMatrix
         * @type {Phaser.Math.Matrix4}
         * @since 3.50.0
         */
        this.viewMatrix = new Matrix4().identity();

        /**
         * The Projection matrix, used by shaders as 'uProjectionMatrix' uniform.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#projectionMatrix
         * @type {Phaser.Math.Matrix4}
         * @since 3.50.0
         */
        this.projectionMatrix = new Matrix4().identity();

        /**
         * A flag indicating if the MVP matrices are dirty, or not.
         *
         * Used by WebGLShader when binding the uniforms.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#mvpDirty
         * @type {boolean}
         * @since 3.50.0
         */
        this.mvpDirty = true;

        /**
         * The configuration object that was used to create this pipeline.
         *
         * Treat this object as 'read only', because changing it post-creation will not
         * impact this pipeline in any way. However, it is used internally for cloning
         * and post-boot set-up.
         *
         * @name Phaser.Renderer.WebGL.WebGLPipeline#config
         * @type {Phaser.Types.Renderer.WebGL.WebGLPipelineConfig}
         * @since 3.50.0
         */
        this.config = config;
    },

    /**
     * Called when the Game has fully booted and the Renderer has finished setting up.
     *
     * By this stage all Game level systems are now in place. You can perform any final tasks that the
     * pipeline may need, that relies on game systems such as the Texture Manager being ready.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#boot
     * @since 3.11.0
     */
    boot: function ()
    {
        var gl = this.gl;
        var config = this.config;

        var target = GetFastValue(config, 'target', false);

        var renderer = this.renderer;

        var width = renderer.width * this.targetScale;
        var height = renderer.height * this.targetScale;

        if (target && width > 0 && height > 0)
        {
            this.targetTexture = renderer.createTextureFromSource(null, width, height, 0);
            this.targetFramebuffer = renderer.createFramebuffer(width, height, this.targetTexture, false);

            // this.targetTexture.flipY = flipY;
        }

        this.setShadersFromConfig(config);

        //  Which shader has the largest vertex size?
        var i;
        var shaders = this.shaders;
        var vertexSize = 0;
        var vertexComponentCount = 0;

        for (i = 0; i < shaders.length; i++)
        {
            if (shaders[i].vertexSize > vertexSize)
            {
                vertexSize = shaders[i].vertexSize;
            }

            if (shaders[i].vertexComponentCount > vertexComponentCount)
            {
                vertexComponentCount = shaders[i].vertexComponentCount;
            }
        }

        this.vertexCapacity = GetFastValue(config, 'vertexCapacity', renderer.config.batchSize * vertexComponentCount);

        var data = GetFastValue(config, 'vertices', new ArrayBuffer(this.vertexCapacity * vertexSize));

        this.vertexData = data;

        if (GetFastValue(config, 'vertices', null))
        {
            this.vertexBuffer = renderer.createVertexBuffer(data, gl.STREAM_DRAW);
        }
        else
        {
            this.vertexBuffer = renderer.createVertexBuffer(data.byteLength, gl.STREAM_DRAW);
        }

        this.bytes = new Uint8Array(data);

        this.vertexViewF32 = new Float32Array(data);

        this.vertexViewU32 = new Uint32Array(data);

        //  Set-up shaders

        this.renderer.setVertexBuffer(this.vertexBuffer);

        for (i = 0; i < shaders.length; i++)
        {
            shaders[i].setAttribPointers(true);
        }

        this.currentShader.bind();

        this.hasBooted = true;

        return this;
    },

    /**
     * Resets the model, projection and view matrices to identity matrices.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#mvpInit
     * @since 3.50.0
     */
    mvpInit: function ()
    {
        this.modelMatrix.identity();
        this.projectionMatrix.identity();
        this.viewMatrix.identity();
    },

    /**
     * Creates a brand new WebGLPipeline instance based on the configuration object that
     * was used to create this one.
     *
     * The new instance is returned by this method. Note that the new instance is _not_
     * added to the Pipeline Manager. You will need to add it yourself should you require so.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#mvpInit
     * @since 3.50.0
     *
     * @param {string} name - The new name to give the cloned pipeline.
     *
     * @return {Phaser.Renderer.WebGL.WebGLPipeline} A clone of this WebGLPipeline instance.
     */
    clone: function (name)
    {
        var clone = new WebGLPipeline(this.config);

        clone.name = name;

        return clone;
    },

    /**
     * Sets the currently active shader within this pipeline.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#setShader
     * @since 3.50.0
     *
     * @param {number} index - The index of the shader to set.
     *
     * @return {this} This WebGLPipeline instance.
     */
    setShader: function (index)
    {
        var shader = this.shaders[index];

        if (shader)
        {
            shader.bind();

            this.currentShader = shader;
        }

        return this;
    },

    /**
     * Searches all shaders in this pipeline for one matching the given name, then returns it.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#getShaderByName
     * @since 3.50.0
     *
     * @param {string} name - The index of the shader to set.
     *
     * @return {Phaser.Renderer.WebGL.WebGLShader} The WebGLShader instance, if found.
     */
    getShaderByName: function (name)
    {
        var shaders = this.shaders;

        for (var i = 0; i < shaders.length; i++)
        {
            if (shaders[i].name === name)
            {
                return shaders[i];
            }
        }
    },

    /**
     * Destroys all shaders currently set in the `WebGLPipeline.shaders` array and then parses the given
     * `config` object, extracting the shaders from it, creating `WebGLShader` instances and finally
     * setting them into the `shaders` array of this pipeline.
     *
     * This is a destructive process. Be very careful when you call it, should you need to.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#setShadersFromConfig
     * @since 3.50.0
     *
     * @param {Phaser.Types.Renderer.WebGL.WebGLPipelineConfig} config - The configuration object for this WebGL Pipeline.
     *
     * @return {this} This WebGLPipeline instance.
     */
    setShadersFromConfig: function (config)
    {
        var i;
        var shaders = this.shaders;
        var renderer = this.renderer;

        for (i = 0; i < shaders.length; i++)
        {
            shaders[i].destroy();
        }

        var vName = 'vertShader';
        var fName = 'fragShader';
        var uName = 'uniforms';
        var aName = 'attributes';

        var defaultVertShader = GetFastValue(config, vName, null);
        var defaultFragShader = Utils.parseFragmentShaderMaxTextures(GetFastValue(config, fName, null), renderer.maxTextures);
        var defaultUniforms = GetFastValue(config, uName, null);
        var defaultAttribs = GetFastValue(config, aName, null);

        var configShaders = GetFastValue(config, 'shaders', []);

        var len = configShaders.length;

        if (len === 0)
        {
            this.shaders = [ new WebGLShader(this, 'default', defaultVertShader, defaultFragShader, DeepCopy(defaultAttribs), defaultUniforms) ];
        }
        else
        {
            var newShaders = [];

            for (i = 0; i < len; i++)
            {
                var shaderEntry = configShaders[i];

                var name = GetFastValue(shaderEntry, 'name', 'default');

                var vertShader = GetFastValue(shaderEntry, vName, defaultVertShader);
                var fragShader = Utils.parseFragmentShaderMaxTextures(GetFastValue(shaderEntry, fName, defaultFragShader), renderer.maxTextures);
                var attributes = GetFastValue(shaderEntry, aName, defaultAttribs);
                var uniforms = GetFastValue(shaderEntry, uName, defaultUniforms);

                newShaders.push(new WebGLShader(this, name, vertShader, fragShader, DeepCopy(attributes), uniforms));
            }

            this.shaders = newShaders;
        }

        this.currentShader = this.shaders[0];

        return this;
    },

    /**
     * Custom pipelines can use this method in order to perform any required pre-batch tasks
     * for the given Game Object. It must return the texture unit the Game Object was assigned.
     *
     * @method Phaser.Renderer.WebGL.Pipelines.WebGLPipeline#setGameObject
     * @since 3.50.0
     *
     * @param {Phaser.GameObjects.GameObject} gameObject - The Game Object being rendered or added to the batch.
     * @param {Phaser.Textures.Frame} [frame] - Optional frame to use. Can override that of the Game Object.
     *
     * @return {number} The texture unit the Game Object has been assigned.
     */
    setGameObject: function (gameObject, frame)
    {
        if (frame === undefined) { frame = gameObject.frame; }

        this.currentUnit = this.renderer.setTextureSource(frame.source);

        return this.currentUnit;
    },

    /**
     * Check if the current batch of vertices is full.
     *
     * You can optionally provide an `amount` parameter. If given, it will check if the batch
     * needs to flush _if_ the `amount` is added to it. This allows you to test if you should
     * flush before populating the batch.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#shouldFlush
     * @since 3.0.0
     *
     * @param {integer} [amount=0] - Will the batch need to flush if this many vertices are added to it?
     *
     * @return {boolean} `true` if the current batch should be flushed, otherwise `false`.
     */
    shouldFlush: function (amount)
    {
        if (amount === undefined) { amount = 0; }

        return (this.vertexCount + amount >= this.vertexCapacity);
    },

    /**
     * Resizes the properties used to describe the viewport.
     *
     * This method is called automatically by the renderer during its resize handler.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#resize
     * @since 3.0.0
     *
     * @param {number} width - The new width of this WebGL Pipeline.
     * @param {number} height - The new height of this WebGL Pipeline.
     *
     * @return {this} This WebGLPipeline instance.
     */
    resize: function (width, height)
    {
        this.width = width;
        this.height = height;

        this.projectionMatrix.ortho(0, width, height, 0, -1000, 1000);

        //  Resize the target?
        var target = this.targetTexture;

        if (target)
        {
            width *= this.targetScale;
            height *= this.targetScale;

            var renderer = this.renderer;

            renderer.deleteFramebuffer(this.targetFramebuffer);
            renderer.deleteTexture(target);

            this.targetTexture = renderer.createTextureFromSource(null, width, height, 0);
            this.targetFramebuffer = renderer.createFramebuffer(width, height, this.targetTexture, false);

            // this.targetTexture.flipY = flipY;
        }

        this.mvpDirty = true;

        return this;
    },

    /**
     * This method is called every time the Pipeline Manager makes this pipeline the currently active one.
     *
     * It binds the resources and shader needed for this pipeline, including setting the vertex buffer
     * and attribute pointers.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#bind
     * @since 3.0.0
     *
     * @param {boolean} [reset=false] - Should the pipeline be fully re-bound after a renderer pipeline clear?
     * @param {number} [shader=0] - If this is a multi-shader pipeline, which shader should be bound?
     *
     * @return {this} This WebGLPipeline instance.
     */
    bind: function (reset, shader)
    {
        if (reset === undefined) { reset = false; }

        if (shader !== undefined)
        {
            this.setShader(shader);
        }

        this.currentShader.bind(false);

        this.renderer.setVertexBuffer(this.vertexBuffer);

        this.currentShader.setAttribPointers(reset);

        return this;
    },

    /**
     * This method is called every time a **Game Object** asks the Pipeline Manager to use this pipeline.
     *
     * Unlike the `bind` method, which is only called once per frame, this is called for every object
     * that requests use of this pipeline, allowing you to perform per-object set-up, such as loading
     * shader uniform data.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#onBind
     * @since 3.0.0
     *
     * @param {Phaser.GameObjects.GameObject} [gameObject] - The Game Object that invoked this pipeline, if any.
     *
     * @return {this} This WebGLPipeline instance.
     */
    onBind: function ()
    {
        if (this.targetTexture)
        {
            this.renderer.setFramebuffer(this.targetFramebuffer);
        }

        return this;
    },

    /**
     * This method is called once per frame, right before anything has been rendered, but after the canvas
     * has been cleared. If this pipeline has a targetTexture, it will be cleared.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#onPreRender
     * @since 3.0.0
     *
     * @return {this} This WebGLPipeline instance.
     */
    onPreRender: function ()
    {
        var gl = this.gl;
        var renderer = this.renderer;
        var target = this.targetTexture;

        if (target)
        {
            renderer.setFramebuffer(this.targetFramebuffer);

            gl.clearColor(0, 0, 0, 0);

            gl.clear(gl.COLOR_BUFFER_BIT);

            renderer.setFramebuffer(null, false);
        }

        return this;
    },

    /**
     * This method is called once per frame, for every Camera in a Scene that wants to render.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#onRender
     * @since 3.0.0
     *
     * @param {Phaser.Scene} scene - The Scene being rendered.
     * @param {Phaser.Cameras.Scene2D.Camera} camera - The Scene Camera being rendered with.
     *
     * @return {this} This WebGLPipeline instance.
     */
    onRender: function ()
    {
        return this;
    },

    /**
     * This method is called once per frame, after all rendering has happened and snapshots have been taken.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#onPostRender
     * @since 3.0.0
     *
     * @return {this} This WebGLPipeline instance.
     */
    onPostRender: function ()
    {
        return this;
    },

    /**
     * Uploads the vertex data and emits a draw call for the current batch of vertices.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#flush
     * @since 3.0.0
     *
     * @return {this} This WebGLPipeline instance.
     */
    flush: function ()
    {
        var gl = this.gl;
        var vertexCount = this.vertexCount;
        var topology = this.topology;
        var vertexSize = this.currentShader.vertexSize;

        if (vertexCount === 0)
        {
            return;
        }

        gl.bufferSubData(gl.ARRAY_BUFFER, 0, this.bytes.subarray(0, vertexCount * vertexSize));
        gl.drawArrays(topology, 0, vertexCount);

        this.vertexCount = 0;

        return this;
    },

    /**
     * Adds the vertices data into the batch and flushes if full.
     *
     * Assumes 6 vertices in the following arrangement:
     *
     * ```
     * 0----3
     * |\  B|
     * | \  |
     * |  \ |
     * | A \|
     * |    \
     * 1----2
     * ```
     *
     * Where tx0/ty0 = 0, tx1/ty1 = 1, tx2/ty2 = 2 and tx3/ty3 = 3
     *
     * @method Phaser.Renderer.WebGL.Pipelines.MultiPipeline#batchQuad
     * @since 3.12.0
     *
     * @param {number} x0 - The top-left x position.
     * @param {number} y0 - The top-left y position.
     * @param {number} x1 - The bottom-left x position.
     * @param {number} y1 - The bottom-left y position.
     * @param {number} x2 - The bottom-right x position.
     * @param {number} y2 - The bottom-right y position.
     * @param {number} x3 - The top-right x position.
     * @param {number} y3 - The top-right y position.
     * @param {number} u0 - UV u0 value.
     * @param {number} v0 - UV v0 value.
     * @param {number} u1 - UV u1 value.
     * @param {number} v1 - UV v1 value.
     * @param {number} tintTL - The top-left tint color value.
     * @param {number} tintTR - The top-right tint color value.
     * @param {number} tintBL - The bottom-left tint color value.
     * @param {number} tintBR - The bottom-right tint color value.
     * @param {(number|boolean)} tintEffect - The tint effect for the shader to use.
     * @param {WebGLTexture} [texture] - WebGLTexture that will be assigned to the current batch if a flush occurs.
     * @param {integer} [unit=0] - Texture unit to which the texture needs to be bound.
     *
     * @return {boolean} `true` if this method caused the batch to flush, otherwise `false`.
     */
    batchQuad: function (x0, y0, x1, y1, x2, y2, x3, y3, u0, v0, u1, v1, tintTL, tintTR, tintBL, tintBR, tintEffect, texture, unit)
    {
        if (unit === undefined) { unit = this.currentUnit; }

        var hasFlushed = false;

        if (this.shouldFlush(6))
        {
            this.flush();

            hasFlushed = true;

            unit = this.setTexture2D(texture);
        }

        var vertexViewF32 = this.vertexViewF32;
        var vertexViewU32 = this.vertexViewU32;

        var vertexOffset = (this.vertexCount * this.currentShader.vertexComponentCount) - 1;

        vertexViewF32[++vertexOffset] = x0;
        vertexViewF32[++vertexOffset] = y0;
        vertexViewF32[++vertexOffset] = u0;
        vertexViewF32[++vertexOffset] = v0;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintTL;

        vertexViewF32[++vertexOffset] = x1;
        vertexViewF32[++vertexOffset] = y1;
        vertexViewF32[++vertexOffset] = u0;
        vertexViewF32[++vertexOffset] = v1;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintBL;

        vertexViewF32[++vertexOffset] = x2;
        vertexViewF32[++vertexOffset] = y2;
        vertexViewF32[++vertexOffset] = u1;
        vertexViewF32[++vertexOffset] = v1;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintBR;

        vertexViewF32[++vertexOffset] = x0;
        vertexViewF32[++vertexOffset] = y0;
        vertexViewF32[++vertexOffset] = u0;
        vertexViewF32[++vertexOffset] = v0;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintTL;

        vertexViewF32[++vertexOffset] = x2;
        vertexViewF32[++vertexOffset] = y2;
        vertexViewF32[++vertexOffset] = u1;
        vertexViewF32[++vertexOffset] = v1;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintBR;

        vertexViewF32[++vertexOffset] = x3;
        vertexViewF32[++vertexOffset] = y3;
        vertexViewF32[++vertexOffset] = u1;
        vertexViewF32[++vertexOffset] = v0;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintTR;

        this.vertexCount += 6;

        return hasFlushed;
    },

    /**
     * Adds the vertices data into the batch and flushes if full.
     *
     * Assumes 3 vertices in the following arrangement:
     *
     * ```
     * 0
     * |\
     * | \
     * |  \
     * |   \
     * |    \
     * 1-----2
     * ```
     *
     * @method Phaser.Renderer.WebGL.Pipelines.MultiPipeline#batchTri
     * @since 3.12.0
     *
     * @param {number} x1 - The bottom-left x position.
     * @param {number} y1 - The bottom-left y position.
     * @param {number} x2 - The bottom-right x position.
     * @param {number} y2 - The bottom-right y position.
     * @param {number} x3 - The top-right x position.
     * @param {number} y3 - The top-right y position.
     * @param {number} u0 - UV u0 value.
     * @param {number} v0 - UV v0 value.
     * @param {number} u1 - UV u1 value.
     * @param {number} v1 - UV v1 value.
     * @param {number} tintTL - The top-left tint color value.
     * @param {number} tintTR - The top-right tint color value.
     * @param {number} tintBL - The bottom-left tint color value.
     * @param {(number|boolean)} tintEffect - The tint effect for the shader to use.
     * @param {WebGLTexture} [texture] - WebGLTexture that will be assigned to the current batch if a flush occurs.
     * @param {integer} [unit=0] - Texture unit to which the texture needs to be bound.
     *
     * @return {boolean} `true` if this method caused the batch to flush, otherwise `false`.
     */
    batchTri: function (x0, y0, x1, y1, x2, y2, u0, v0, u1, v1, tintTL, tintTR, tintBL, tintEffect, texture, unit)
    {
        if (unit === undefined) { unit = this.currentUnit; }

        var hasFlushed = false;

        if (this.shouldFlush(3))
        {
            this.flush();

            hasFlushed = true;

            unit = this.setTexture2D(texture);
        }

        var vertexViewF32 = this.vertexViewF32;
        var vertexViewU32 = this.vertexViewU32;

        var vertexOffset = (this.vertexCount * this.currentShader.vertexComponentCount) - 1;

        // tintEffect = 1;

        vertexViewF32[++vertexOffset] = x0;
        vertexViewF32[++vertexOffset] = y0;
        vertexViewF32[++vertexOffset] = u0;
        vertexViewF32[++vertexOffset] = v0;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintTL;

        vertexViewF32[++vertexOffset] = x1;
        vertexViewF32[++vertexOffset] = y1;
        vertexViewF32[++vertexOffset] = u0;
        vertexViewF32[++vertexOffset] = v1;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintTR;

        vertexViewF32[++vertexOffset] = x2;
        vertexViewF32[++vertexOffset] = y2;
        vertexViewF32[++vertexOffset] = u1;
        vertexViewF32[++vertexOffset] = v1;
        vertexViewF32[++vertexOffset] = unit;
        vertexViewF32[++vertexOffset] = tintEffect;
        vertexViewU32[++vertexOffset] = tintBL;

        this.vertexCount += 3;

        return hasFlushed;
    },

    /**
     * Sets a 1f uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set1f
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number} x - The new value of the `float` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set1f: function (name, x)
    {
        this.currentShader.bind().set1f(name, x);

        return this;
    },

    /**
     * Sets a 2f uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set2f
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number} x - The new X component of the `vec2` uniform.
     * @param {number} y - The new Y component of the `vec2` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set2f: function (name, x, y)
    {
        this.currentShader.bind().set2f(name, x, y);

        return this;
    },

    /**
     * Sets a 3f uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set3f
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number} x - The new X component of the `vec3` uniform.
     * @param {number} y - The new Y component of the `vec3` uniform.
     * @param {number} z - The new Z component of the `vec3` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set3f: function (name, x, y, z)
    {
        this.currentShader.bind().set3f(name, x, y, z);

        return this;
    },

    /**
     * Sets a 4f uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set4f
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number} x - X component of the uniform
     * @param {number} y - Y component of the uniform
     * @param {number} z - Z component of the uniform
     * @param {number} w - W component of the uniform
     *
     * @return {this} This WebGLPipeline instance.
     */
    set4f: function (name, x, y, z, w)
    {
        this.currentShader.bind().set4f(name, x, y, z, w);

        return this;
    },

    /**
     * Sets a 1fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set1fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set1fv: function (name, arr)
    {
        this.currentShader.bind().set1fv(name, arr);

        return this;
    },

    /**
     * Sets a 2fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set2fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set2fv: function (name, arr)
    {
        this.currentShader.bind().set2fv(name, arr);

        return this;
    },

    /**
     * Sets a 3fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set3fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set3fv: function (name, arr)
    {
        this.currentShader.bind().set3fv(name, arr);

        return this;
    },

    /**
     * Sets a 4fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set4fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set4fv: function (name, arr)
    {
        this.currentShader.bind().set4fv(name, arr);

        return this;
    },

    /**
     * Sets a 1iv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set1iv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set1iv: function (name, arr)
    {
        this.currentShader.bind().set1iv(name, arr);

        return this;
    },

    /**
     * Sets a 2iv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set2iv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set2iv: function (name, arr)
    {
        this.currentShader.bind().set2iv(name, arr);

        return this;
    },

    /**
     * Sets a 3iv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set3iv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set3iv: function (name, arr)
    {
        this.currentShader.bind().set3iv(name, arr);

        return this;
    },

    /**
     * Sets a 4iv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set4iv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {number[]|Float32Array} arr - The new value to be used for the uniform variable.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set4iv: function (name, arr)
    {
        this.currentShader.bind().set4iv(name, arr);

        return this;
    },

    /**
     * Sets a 1i uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set1i
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {integer} x - The new value of the `int` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set1i: function (name, x)
    {
        this.currentShader.bind().set1i(name, x);

        return this;
    },

    /**
     * Sets a 2i uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set2i
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {integer} x - The new X component of the `ivec2` uniform.
     * @param {integer} y - The new Y component of the `ivec2` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set2i: function (name, x, y)
    {
        this.currentShader.bind().set2i(name, x, y);

        return this;
    },

    /**
     * Sets a 3i uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set3i
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {integer} x - The new X component of the `ivec3` uniform.
     * @param {integer} y - The new Y component of the `ivec3` uniform.
     * @param {integer} z - The new Z component of the `ivec3` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    set3i: function (name, x, y, z)
    {
        this.currentShader.bind().set3i(name, x, y, z);

        return this;
    },

    /**
     * Sets a 4i uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#set4i
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {integer} x - X component of the uniform
     * @param {integer} y - Y component of the uniform
     * @param {integer} z - Z component of the uniform
     * @param {integer} w - W component of the uniform
     *
     * @return {this} This WebGLPipeline instance.
     */
    set4i: function (name, x, y, z, w)
    {
        this.currentShader.bind().set4i(name, x, y, z, w);

        return this;
    },

    /**
     * Sets a matrix 2fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#setMatrix2fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {boolean} transpose - Whether to transpose the matrix. Should be `false`.
     * @param {number[]|Float32Array} matrix - The new values for the `mat2` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    setMatrix2fv: function (name, transpose, matrix)
    {
        this.currentShader.bind().setMatrix2fv(name, transpose, matrix);

        return this;
    },

    /**
     * Sets a matrix 3fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#setMatrix3fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {boolean} transpose - Whether to transpose the matrix. Should be `false`.
     * @param {Float32Array} matrix - The new values for the `mat3` uniform.
     *
     * @return {this} This WebGLPipeline instance.
     */
    setMatrix3fv: function (name, transpose, matrix)
    {
        this.currentShader.bind().setMatrix3fv(name, transpose, matrix);

        return this;
    },

    /**
     * Sets a matrix 4fv uniform value based on the given name on the currently set shader.
     *
     * The current shader is bound, before the uniform is set, making it active within the
     * WebGLRenderer. This means you can safely call this method from a location such as
     * a Scene `create` or `update` method. However, when working within a Shader file
     * directly, use the `WebGLShader` method equivalent instead, to avoid the program
     * being set.
     *
     * @method Phaser.Renderer.WebGL.WebGLShader#setMatrix4fv
     * @since 3.50.0
     *
     * @param {string} name - The name of the uniform to set.
     * @param {boolean} transpose - Should the matrix be transpose
     * @param {Float32Array} matrix - Matrix data
     *
     * @return {this} This WebGLPipeline instance.
     */
    setMatrix4fv: function (name, transpose, matrix)
    {
        this.currentShader.bind().setMatrix4fv(name, transpose, matrix);

        return this;
    },

    /**
     * Destroys all shader instances, removes all object references and nulls all external references.
     *
     * @method Phaser.Renderer.WebGL.WebGLPipeline#destroy
     * @since 3.0.0
     *
     * @return {this} This WebGLPipeline instance.
     */
    destroy: function ()
    {
        var shaders = this.shaders;

        for (var i = 0; i < shaders.length; i++)
        {
            shaders[i].destroy();
        }

        this.gl.deleteBuffer(this.vertexBuffer);

        this.game = null;
        this.renderer = null;
        this.gl = null;
        this.view = null;
        this.shaders = null;
        this.vertexData = null;
        this.vertexBuffer = null;

        return this;
    }

});

module.exports = WebGLPipeline;